Outline

Objective: To review the number of patients and treatment modality for patients with unruptured intracranial aneurysms (UIA) with regard to successful obliteration and complications by each treatment option.

Methods: Data derived from a large prospective data base of intracranial aneurysms from June 1999 through may 2005 with all patients having a 6 month follow-up. Six month outcome was assessed according to the modified Rankin Scale (mRS) and was classified as good outcome with a mRS 0-2. Out of a total of 691 patients included in the data base, 174 patients were identified to be harboring 252 UIA. 82 patients (96UIA) had microsurgical and 36 patients (37UIA) endovascular obliteration of the aneurysm. 55 patients (119 UIA) were not treated during the observation period because of death or poor clinical condition after previous subarachnoid hemorrhage (SAH), small size of the aneurysm or refused treatment.

Results: All aneurysms were successfully obliterated and no patient suffered from SAH after treatment during the observation period. There was no death related to any treatment in this series. 112 of the 118 treated patients had a good outcome at 6 months. 5 of the surgically treated patients had 6 months mRS 3-6 (2 patients had mRS 4 prior to treatment of the UIA due to previous SAH, 3 patients were treated for large or giant aneurysms with postoperative deterioration of mRS). 1 patient with endovascular obliteration of a basilar aneurysm had a mRS of 3. Analysis of the overall complication rate showed that symptomatic complications occurred in 6 (7.3%) of 82 patients (1 ICH, 5 ischemia) after surgical obliteration. During endovascular treatment, thromboemboilc complications were managed in 3 patients by thrombolysis without infarction and 3 patients (8.3%) had new symptomatic postintervention infarction. Small residual aneurysm necks were found in 12.5% of surgical and 30% in the endovascular aneurysms in the post treatment 3D-angiography, which had to be left to avoid parent vessel narrowing or stenosis of branching vessels involved in aneurysm basis. 4 patients underwent recurrent endovascular treatment after aneurysm re-canalization.

Conclusions: The outcome of our patients with UIA was not dependent on treatment modality. However the rate of recanalization of UIA is higher after endovascular obliteration. After diagnosing an UIA, an individual interdisciplinary decision is essential for each patient in order to achieve a good outcome.